Donald Trump’s habit of making threats off the cuff, such as his “fire and fury” remarks about North Korea, may be unnerving. But let us be charitable, or optimistic, and concede that it is possible that his unconventional approach to international affairs may have an upside. Problems that have persisted for years or even decades, from the illegal occupation of Palestine to the growing nuclear capabilities of the Pyongyang regime, could – just could – maybe benefit from someone who comes anew to past attempts to solve them, none of which, after all, have succeeded.

The resolution, decisiveness and power that the US president wishes to project could have positive effects. It is too early to tell as yet. But what is clear is that Mr Trump must be more collegiate and clever if the American assertiveness he wants to exercise is to provide the “wins” he has long promised to notch up.

His comments on Venezuela are a case in point. The country’s decline under Nicolas Maduro, its president, has been tragic – especially for those who saw the years under his predecessor, Hugo Chavez, as offering a model of a “socialism that works”, albeit one underpinned by massive oil revenues during a period when the price per barrel was generally far higher than today.

Mr Maduro, on the other hand, lacks not only the charisma of “El Comandante”, but also his popularity, his luck and any semblance of knowing how to improve the country's dire finances. Venezuela is not only failing economically; its democracy is being dismantled so grievously that on August 4, Brazil’s foreign minister, Aloysio Nunes, declared: “It is intolerable that we have a dictatorship in the South American continent.”

The very next day Mercosur, the regional trading bloc, voted to suspend Venezuela for “rupture of the democratic order”, saying the country would not be returned to normal membership until democracy was restored.

As Mr Maduro attempted to replace the democratically elected national assembly with his illegal constitutional convention packed with his placemen, even previous allies, such as Britain's Jeremy Corbyn, found themselves unable to find anything to say in his defence. The Venezuelan leader appeared increasingly isolated.

That is until Mr Trump surprised the world – and quite possibly the secretaries of state and defence, certainly Gen McMaster who ruled out such a scenario earlier this month – by saying, “We have many options for Venezuela, including a possible military option if necessary.” That same evening Mr Trump refused to speak to Mr Maduro when he tried to phone. “President Trump will gladly speak with the leader of Venezuela as soon as democracy is restored in that country,” said a rather tart White House statement.

Cue: general uproar.

For it was not just Venezuela's defence minister Vladimir Padrino who attacked Mr Trump’s threat of armed intervention as "an act of madness".

The foreign minister of Peru, Ricardo Luna, quickly responded: "All foreign or domestic threats to resort to force undermine the goal of reinstating democratic governance in Venezuela, as well as the principles enshrined in the UN charter." That was not from a friend of the Maduro regime, but from a government that had just played tit-for-tat expulsion of ambassadors with Venezuela.

President Juan Manuel Santos of Colombia, again, no ally of the Chavistas, was equally firm during a visit by Vice President Pence on Sunday. “The possibility of military intervention shouldn't even be considered," he said. "The Latin American continent, every country in Latin America, would not favour any form of military intervention. A transition in the Venezuelan regime toward democracy must be a peaceful transition.”

So Mr Trump’s likely casual mention of military force in fact succeeded in uniting all Mr Maduro’s enemies – what Mark Schneider of the Center for Strategic and International Studies has called “the strongest Latin American consensus in support of democracy that I have seen since the end of the Pinochet regime” – in his support instead.

As David Smilde, senior fellow at the Washington Office on Latin America, put it to Reuters: “Maduro could not have asked for a greater gift from Trump. He provided substance for Maduro's heretofore implausible conspiracy theories."

This ought to have been obvious. America’s history of interventions in the region is long, inglorious and mired in hypocrisy, from its condoning the coup against Chile’s Salvador Allende in 1973, to its overthrowing of the former CIA asset General Noriega in Panama in 1989, to its coordination of a coup against Mr Chavez in 2002. The latter was reversed after 48 hours, and the Bush White House tried to distance itself from the plot, but it has not been forgotten – and not just by the Chavistas.

Mr Trump’s wish to help Venezuela – where 120 people have died during protests over the last four months – is admirable, as is his desire to bring an end to North Korea’s nuclear menace. But he remains dangerously uninformed about the context and the past of such countries.

We know he doesn’t like reading books, and prefers to get his news from the TV. Perhaps his new chief of staff Gen Kelly can ensure it is switched permanently to the History Channel. Otherwise Mr Trump’s words – let alone his deeds – risk bringing about precisely the opposite of what he aims for.

Sholto Byrnes is a senior fellow at the Institute of Strategic and International Studies, Malaysia